Internal-combution engine.



No. 746,925. EATENTEE EEG'. 15, 1903;

E N. CRANE.v

INTERNAL GOMBUSTION ENGINE.

APPLIU'ATION EIILED MAY 1.1902..

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No MODEL.

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No. 746,925. v A PATNNTED DNG.15,1903.

N. GNANE. L INTERNAL GOMBUSNION ENGINE.

APPLIGATION FILED MAY 1, 1902. Y

2 SHEETS-SHEET 2.

l UNITED STATES i :Patented December 15, 1903.

PATENT OFFICE.

NEWTON CRANE, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO NEWTON CRANE GAS ENGINE COMPANY, OF BOSTON, MASSACHUSETTS, A COR- PORATION OF MAINE.

INTERNAL-COM BUSvTlON ENGINE.v

SPECIFICATION fOrmng part of Letters Patent No. 746,925, dated December 15, 1903. Application led May 1, 1962. Serial No. 105,462. (No model.)

To all whom iv' may concern:v

`Be itknown that I, NEWTON CRANE, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain newv and useful Improvements in Internal- Combustion Engines, of which the following is aspecication. Y

This invention has relation to internal-combustion engines, and has for its object to provide certain improvements therein by means of which the indicated horse-power may be increased and the actual Weight of the engine decreased. In accomplishing this object I have aimed te provide certain structural improvements .for enhancing the general eiliciency of engines of the type referred to, as will be fully explained in the following specication. Y

Referring to the drawings, Figure 1 represents in horizontal section an engine embodying the invention. Fig. 2 represents a section on the line 2 2 of Fig. 1.-

the line of the axis of the crank-shaft. Fig. 5 represents a section on the line 5 5 of Fig. 1 and illustrates the valve mechanism.

According to the invention two separate cylinders 10 10 are arranged in parallelism, as shown in Fig. 1., Each cylinder is similar in construction to the cylinder illustrated in my copending application, Serial No. 103,112, filed April 16, 1902, to which reference may be had for a more detailed description than is herein given. It may be stated generally, however, that each cylinder is provided with au inner bushing 11, of cast metal, on which is shrunk a sleeve 12, of drawn metal, such as tubing.- At the ends of each cylinder are the rings 13 13, of wrought-iron, which form the ends ofthe water-jacket 14 when the casing 15, otdrawn tubing, is shrunk thereon. Midway between the ends of each cylinder are the duplex rings 16 and the additional rings 17 17, which, like the rings 16, are notched to provide for the free circulation of the water or other cooling medium. The ends of the two cylinders are closed by two pairs of heads 18 18, each pair of heads being cast 5o in one piece with a connecting-Web 19, as

Fig. 3 represents a section on the line 3 3 of Fig. 1. Fig. f1 represents a section through the engine on shown in Fig. 3. These heads are hollow, as shown in Figs.- 1 and 2, and they afford bearings for the parallel rock-shafts 19 19, which are disposed. one above the other below the cylinders, as shown in Fig. 2. The heads are secured by screws or bolts 24 to rings 25, shrunk upon the ends of the cylinders, as clearly portrayed in Fig. l. In each cylinsimultaneously in opposite directions. The

movement of the two pistons at the correspending' ends of the two cylinders is synchronous. Each piston is connected by a cross-bar 21 and a pitman 22 with an arm 23 on one of the rock-shafts 19, and when the pistons are at the endy of their compressionstrokethe said pitman lies substantially parallel to the central median line of the cylinders. The movement of the pistons out and in eects a rocking of the shafts 19, the a'ngularity of the pitmen 22 increasing but slightly as the pistons reach their outer extremes of movement, and consequently power is applied almost directly to the shafts 19. Each pitman forms, with' its connected arm, an obtuse angle whenthe piston is at the end of its compression stroke. As the piston moves outward the angle changes to a right angle and then to an acute angle; but the rei sive with the movement ot' the piston, and

consequently there is no lost motion, as where a crank passes a dead-center.

The crank or engine shaft is indicated at 27. Itis journaled in bushings 28,arranged Within water-jacketing extensible tubes 29, whose ends are secured in the duplex rings 16 16, as shown in Fig. l. These bushings and tubes extend through the cylinders and are arranged between the pistons, as shown in Fig. 2, so that the axis of the crank-shaft intersects the median longitudinal lines of the two cylinders. Each tube 29 is formed with two telescoping parts to provide for the expan- 'sion and contraction, and their ends are held in place by ilanges 30 on the bushings 28 and nuts 31,screwed on the outer end of said hushings. The compartments or water-chambers 32, which surround the bushings, communi- Ader there are two pistons 20 20, which move ICQ cate by suitable ports 33 with the waterchambers 14 of the cylinders, so that water may be pumped through said chambers at a rapid rate, the discharge being through the eduction-pipes 34 at the ends of said cylinders. Water is supplied to said chambers from the water-chambers in the valve-casings,

-Which will be subsequently referred to.

vThe two cranks 38 38 are connected, respectively, by pitmen 39 with arms 40 on the shafts 19, as shown in Fig. 3, said arms 40 lying parallel to the arms 23 on the same shaft. The two cranks 38 extend in opposite directions and their throw is such that when an arm 23 moves outward to its limit through an arc of about ninety degrees the cranks traverse an arc of one hundred and eighty degrees.

Upon the crank-shaft 27 is a momentumwheel 43, arranged at one end thereof. On the other end of the shaft is a power-transmitting member 44, such as a sprocket or gear Wheel. The crank-shaft also carries on its extremity a sprocket-wheel 45, by which power is transmitted to the valve-controlling mechanism.

The valve-Casin gs are indicated at 50. They are formed separately and are bolted to the ringsl and 17 by bolts 51, as shown in Fig. 3. Each casing has the chamber 52, which communicates through a port 53 with the cylinder, as shown in Fig. 2, there being an opening in the duplex ring 16 for the formation of this port,-as illustrated in the copending application hereiubefore referred to. Each valve-casing is further formed with a waterchamber 54, which surrounds the gas-chamber 52 and which communicates by a port 55 with the water-chamber 32 around the crankshaft bushing. Water is supplied to the valve-chambers 54 from a pipe 56, having .a T-coupling 57 at the end thereof, as shown in Fig. 4.

To supply explosive mixture to the chambers 52, there is a pipe 59, having the T-coupling 60, leading into the conduits 61 6l in the two casings. These two conduits communicate with the valve-seats 62, screwed into the side of the casing, as best illustrated in Fig. 5.

The ingress-valves are indicated at 63 and are held against their seats by springs 64, coiled about the stems thereof and bearing against heads 65 on the said stems. These springs are light enough to permit the opening of the valve when the pressure is red uced in the chambers 52.

The eduction-valves 66 are held normally against their seats by springs 67, bearing against heads 68 on the stems of said valves. They close the eduction-ports which lead to the conduits 69, with which communicate the branches of a T-coupling 70 of an exhaust-pipe 71. For positively opening the eduction or exhaust valves there is employed a shaft 72, journaled in bearings afforded by brackets 73 on the valve-casings and having oppositely-di'sposed cams 74 in position to coact with the heads 68 of the valves 66.

The cam shaft 72 is equipped with a sprocket 75, connected by an endless chain 76 with the sprocket-Wheel 45 on the crankshaft 27. The ratio of the two sprocketwheels is such that the shaft 72 is rotated once for each two rotations of the crank-sh aft.

Each of the gas-chambers 52 is equipped with a sparking plug, and suitable mechanism is provided for causing a spark in the chamber at the proper times. This mechanism is not shown, but is portrayed in my copending application, to which reference has been previously made herein.

The construction and arrangement of parts as thus described provide for the simultaneous movement of the pistons in and out; but at the same time the working stroke of the pistons in one cylinder is synchronous with the charging stroke of the pistons in the other cylinder, and vice versa, so that the first half of each rotation of the crank-shaft is positively eected as a result of the coinbustion of the explosive mixture in either one or the other of the cylinders. The location of the crank-shaft in the plane of movement of the pistons provides a compactarrangement of parts and enables me to secure other benefits, which will be apparent to those skilled in the art to which this invention relates. One of these benefits or advantages, is that the pitmen 22 and 39, which, respectively,connect the pistons and the cranks with the rock-shafts, work substantially in parallelism during the operative stroke of the piston, and the angularity of the pitmen 22 to the pistons is of small moment,thereby greatly reducing the lateral pressure of the pistons against the walls of the cylinders and the frictional resistance to the movement of the pistons. Another of the important benefits achieved by this arrangement of the rockshaft, crank-shaft, pistons, and connectingrods is that I secure a relatively rapid movement of the piston at the first part of its stroke and aslower movement at the end of its stroke, and consequently instead of the heat generated by the combustion being dissipated by radiation it is transformed into force. Where the piston is connected directly with the crank, the axis of which intersects the axis of the piston, the first movement of the piston outward is relatively slow, owing to the fact that the crank moves from a deadcenter position to an angle with the connecting-rod, and although the crank itself moves through arelatively large arc during the initial stroke of the piston, yet the movement of the piston is comparatively slower and is less. than its movement when the crank moves through another arc of the same length as the piston moves farther toward its outer limit. With my invention the disposal of the rock-shaftk out of alinement with the axis of the piston provides for the connection of the crank-pitmen 39 and the piston-pitmen 22 with the arms 23 and 4() at an obtuse angle thereto when the piston is at its starting- IOO IIO

pointto wit, at the end of its compressionstroke. Consequently the initial movement of the piston for the same arc of movement of the crank-shaft is greater than where the piston is connected directly with the crankshaft, with the result that greater power is transmitted to the crank-shaft, and the vheat generated by the combustion is dissipated by its transformation into force rather than by radiation, as previously stated.

Having thus explained the nature of the invention and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it may be made or all of the modes of its use, I declare that what I claim isl. An internal-combustion engine comprising a cylinder having oppositely-movable pistons, a crank-shaft located between said pistons, a rock-shaft at each end of the cylinder, said rock-shafts being on opposite sides of the median line of said cylinder, connections between the pistons and the rock-shafts, and connections between the rock-shafts and the said crank-shaft. Y

2. An internal-combustion engine comprising a cylinder having oppositely-movable pistons, a crank-shaft located between said pistons, rock-shafts at the ends of the cylinder on opposite sides of the axis of said cylinder, a pair of arms on each rock-shaft, the arms on one rock-shaft extending in an opposite direction to the arms of the other rock-shaft, and pitmen connecting the arms ot' each rockshaft with the crank-shaft and a piston respectively.

3. An internal-combustion engine comprising parallel cylinders having oppositely-movable pistons, heads on said cylinders, the

heads on the corresponding ends of the cylinders being connected, rock-shafts journaled in said heads, arms on said rock-shafts connected to said pistons, a crank-shaft parallel to the rock-shafts and located midway between them, and arms on the said rock-shafts connected to the said crank-shaft.

4. An internal-combustion engine comprising parallel cylinders having oppositely-movable pistons, rock-shafts located at the ends of said cylinders, each rock -shaft having three substantially parallel arms, the arms of oneA rock-shaft extending in a direction opposite the arms of the other rock-shaft, a crankshaft located in parallelism with the rockshatts and substantially midway between them, pitmen .connecting one arm of each rock-shaft with the crank-shaft, and pitmen connecting the other two arms on ea'ch rockshaft with the pistons in the cylinders.

5. An internal-combustion engine comprising a pair of parallel cylinders, a pair of oppositely-moving pistons in each cylinder, a crank-shaft, and connections between said pistons and said crank-shaft comprising a pair of rock-shafts, arms on said shafts and rods connecting said arms with said crankshaft and said pistons, said parts being arranged and constructed whereby the pistons move the same extent in unison a greater distance with relation to an arc of movement of the crank-shaft at the initial portion of its stroke, than with relation to a similar arc of movement during the end of its stroke.

In testimony whereof I have aixed my signature in presence of two witnesses.

NEWTON CRANE.

Witnesses MARCUS B. MAY, C. C. 'Sfrncnna 

